Skip to content

Simulations & Solvers

FDTD, Low-Frequency, Neuron, Mode-Matching, Flow, Acoustics, etc...

237 Topics 703 Posts

Subcategories


  • FDTD, Low-Frequency, Neuron, Mode-Matching, Flow, Acoustics, etc...

    11 27
    11 Topics
    27 Posts
    N
    Hi! Can someone help me understand if it makes sense to calculate SAR statistics in a low frequency electrical stimulation (30 Hz)? Thanks!!
  • LF EQS solver diverged/failed

    divergence low-frequency
    1
    0 Votes
    1 Posts
    387 Views
    No one has replied
  • I'm modeling TEM cell, which is device for generating a electric field

    3
    0 Votes
    3 Posts
    276 Views
    R
    @ofli Thank you for texting. Yes. I set up the similar one. I adjusted the size to the edge of the TEMcell tho.
  • Can Acoustic solver works with Flow solver?

    2
    0 Votes
    2 Posts
    187 Views
    brynB
    I am not aware of any coupling implemented for this combination.
  • Programmatically set source settings (neuro)

    1
    1 Votes
    1 Posts
    148 Views
    No one has replied
  • How to use a script to automatically open an already run simulation

    3
    0 Votes
    3 Posts
    301 Views
    S
    @pyf Hi, This is what I found in the tutorial scripts for thermal simulations. Check the RunTutorial function. It may help. Best. def CreateModel(): ... def CreateEmFdtdSimulation(): ... return em_sim def CreateThermalSimulation(em_sim): ... return thermal_sim def AnalyzeEmAndThermalSimulation(em_sim,thermal_sim): # Create extractor for the two simulation output files em_results = em_sim.Results() thermal_results = thermal_sim.Results() # overall field sensors em_overall_field_sensor = em_results[ 'Overall Field' ] em_overall_field_sensor.Normalization.Normalize = True thermal_overall_field_sensor = thermal_results[ 'Overall Field' ] # Create a slice viewer for the SAR slice_field_viewer_sar = analysis.viewers.SliceFieldViewer() slice_field_viewer_sar.Visualization.Smooth = True slice_field_viewer_sar.Inputs[0].Connect( em_overall_field_sensor['SAR(x,y,z,f0)'] ) slice_field_viewer_sar.Update(0) slice_field_viewer_sar.GotoMaxSlice() document.AllAlgorithms.Add( slice_field_viewer_sar ) #THERMAL slice_field_viewer_t = analysis.viewers.SliceFieldViewer() slice_field_viewer_t.Visualization.Smooth = True slice_field_viewer_t.Inputs[0].Connect( thermal_overall_field_sensor['T(x,y,z,t)'] ) slice_field_viewer_t.Update(0) document.AllAlgorithms.Add( slice_field_viewer_t ) def RunTutorial( path ): document.New() CreateModel() em_sim = CreateEmFdtdSimulation() document.AllSimulations.Add(em_sim) em_sim.UpdateGrid() em_sim.CreateVoxels(path) thermal_sim = CreateThermalSimulation(em_sim) document.AllSimulations.Add(thermal_sim) thermal_sim.UpdateGrid() thermal_sim.CreateVoxels(path) em_sim.RunSimulation(wait=True) thermal_sim.RunSimulation(wait=True) AnalyzeEmAndThermalSimulation(em_sim,thermal_sim) if name == 'main': RunTutorial( project_path )
  • 0 Votes
    2 Posts
    211 Views
    S
    @mingjuan Hi, I recommend updating your driver (https://developer.nvidia.com/opengl-driver).
  • EM LF electro simulation

    1
    0 Votes
    1 Posts
    219 Views
    No one has replied
  • Subgrid for Acoustic Simulation, to limit grid size?

    2
    0 Votes
    2 Posts
    225 Views
    M
    There's no subgridding just a rectilinear / adaptive grid (you can create new grid settings and drag and drop solids or wireframes to these) What you can do (at your own 'risk') is manually set the grid to the resolution you want and not use the automatic grid settings. Typically you want at least 10 points per wavelength (more is better) and the wavelength in air (343 / freq) and water (1500 / freq) are quite different.
  • adding inductive decoupling circuits into the model

    1
    0 Votes
    1 Posts
    387 Views
    No one has replied
  • Pulse-Echo Ultrasound Acoustic Simulation Time Domain

    5
    0 Votes
    5 Posts
    420 Views
    M
    Don't worry about the time step, just make sure it's fine enough, Sim4Life will then interpolate your function into it's own timestep as needed (so, you just need to be careful that your timestep is not too coarse such that Sim4Life won't be able to linearly (I think) interpolate it Essentially, the answer is yes, its sufficient
  • SEFT Tutorial Grid Error

    8
    0 Votes
    8 Posts
    734 Views
    M
    Typically 1 MHz is way too large wavelength = speed of sound / frequency resolution = wavelength / 10 so, if you speed of sound in water is 1500 m/s and you want to run a simulation at 100 kHz, then the wavelength is around 15 mm, and the resolution should be at least 1.5mm From the resolution and your domain size you can calculate the grid size Grid Size: max. 20 Mio cells
  • Time domain acoustic simulation- problem with the number of periods

    5
    0 Votes
    5 Posts
    500 Views
    A
    @montanaro That would be of great help. Thank you so much Annalisa
  • SEFT simulation - problems with parameters

    10
    0 Votes
    10 Posts
    716 Views
    M
    I don't remember so well, but I'm pretty sure it's 1/timestep used to discretize / sample the signal. (Note that this is used to create a list of time points and pressure signals, but the acoustic solver then again reinterpolates this signal to it's own time step that is calculated from the Setup Frequency) Setup Frequency is mostly ignored now that you have user defined source, it was mostly used as a frequency of the sources and for the final FFT analysis. However, if I remember correctly it is used to calculate the time step used in the solver, so make sure it is set to the highest frequency available in your sources That expression was just a random signal to give the user an idea of how to input expressions. It seems in your case you want Element 5 to be sin(2 * pi * 0.5E9 *_t) and Element 6 to be sin(2 * pi * 0.75E9 *_t) if you want to excite one transducer at 500 KHz and the other at 750 KHz User defined sources sets an equation which is then sampled / interpolated at that sampling frequency (fs = 1/dt)
  • FDTD Simulation Fail

    2
    0 Votes
    2 Posts
    323 Views
    ofliO
    Dear Aiping, please send the simulation file to the support team. Thanks.
  • This topic is deleted!

    1
    0 Votes
    1 Posts
    2 Views
    No one has replied
  • Different frequencies in electrodes

    13
    0 Votes
    13 Posts
    2k Views
    H
    @pastis Hello, Have you solved this question? can we compare the amount of electric field that reach the targeted region to evaluate the TI simulation ?
  • Neuron solver failed

    2
    0 Votes
    2 Posts
    267 Views
    H
    Hello, It seems that you now have the Neuron installer and it is working, but something is missing in your setup. Could you please check for error messages in the Console? One possible reason could be that you have installed NEURON before Sim4Life completely finished its installation. Please uninstall Sim4Life, install it again, and only after finishing install NEURON.
  • RAM Usage Limit

    2
    0 Votes
    2 Posts
    315 Views
    H
    Hello, Unfortunately there is no direct way from Sim4Life to limit the amount of RAM to allocate for the program. You may be able to do so using external tools that tap into the operating system's settings and manage the resources. But we are not aware of any and we did not test any that we would recommend. The reason your PC is slowing down is because the OS switches to paging on disk instead of using fast RAM. Paging is slow and uses CPU resources. My guess is that even if you limit the RAM for Sim4Life, the solver will still need a lot more memory and it will either fail or use the disk for paging resulting in the similar slowing effect.
  • Magneto Quasi-static simulations stop

    1
    0 Votes
    1 Posts
    213 Views
    No one has replied
  • conformal mesh

    2
    0 Votes
    2 Posts
    244 Views
    brynB
    If the cable bounding box is smaller than the body, maybe you could use sub-gridding.